Accurate Measurement of
Velocity and Acceleration of
Seismic Vibrations near Nuclear
Power Plants
By
Syed Javed Arif
Department of
Electronics Engineering,
A.M.U., Aligarh, India
1
CONTENTS
• INTRODUCTION
• THEORY
• REALIZATION
• EXPERIMENTAL RESULTS
A. When the vibration system is stationary
B. When the system starts vibrating
• CONCLUSION
• REFERENCES
2
INTRODUCTION
• Earthquake causes
• Heavy Desetruction to Buildings and
Structures
• Heavy Economic Losses
• Destruction of Nuclear Power Plants
with its Cosequences
• Heavy losses to Human Lives
3
As an Example Earthquake of
• Japan in 2011 Caused Heavy
Destruction and Nuclear Tragedy
• Haity in 2011 Killed nearly230000
people
• Sumatra (Tsunami) in 2004 killed
more than 300,000 people in 11
countries
4
Drawbacks of Existing Methods of
Measurement are
• instruments like seismometers
Misses the peaks
• Accelerometers, measures only one
parameter ie acceleration
• fails to record the peak values of
acceleration, displacement, speed &
rise time
5
Drawbacks Continued
• due to poor resolution, it causes
problems in the consistent
design of nuclear power plants,
industrial plants and buildings,
resistant to strong earthquakes.
6
In the proposed method
• A microprocessor based vibration
generation system is developed to
generate rocking motion and vibrations.
• The vibration system vibrates the rotor of
synchro back and forth, which ultimately
varies the frequency and voltage in the
rotor circuit.
• It gives the spectrum of pulses which
corresponds to the velocity of seismic
vibrations.
7
THEORY
• The speed of Rotor of Synchro is
given by
and
8
3- ph a s e a c s u ppl y
REALIZATION
Vs(f s ) Synchro S
VA
VB
Vr(f r ) 1K
V R(fR )
311
Stator
Rotor
10K
To OS
ZCD
10K
VC
Stepper motor
(rocking unit)
Microprocessor
based control of
stepper motor
Microprocessor based vibration generation and measurement setup
9
REALIZATION CONTD
Va1
Va2
0
0
100K
0.1µF
0
0
Amp
1
VA
0
1K
Vb2
Vb1
0
10K
Vc1
0
0
0
Amp
2
VB
0
F.G
1K
100K
Vc2
0.1µF
VC
0
1K
0
0
0
Amp
3
0
Single-phase to three-phase voltage conversion system
10
Measured waveforms VA, VB, VC at the output of power amplifiers
(CH#1, CH#2 and Ch#3).
11
Measured three phase voltages, VA, VB, VC at stator winding of
synchro (CH#1, CH#2 and Ch#3). Vr, fr (CH#4).
12
EXPERIMENTAL RESULTS
When the vibration system is stationary
Measured output of rotor, Vr, fr of synchro, S (Ch#4) and Output of ZCD,
VR, fR (Ch#1) at 50 Hz.
13
One Shot ( OS)
C
Signal VR
Q
R
Q
OS
A
&
B
G-1
Signal VR
Signal Q
50 Hz
TWQ+ =10ms
Signal Q´
50 Hz
TWQ- =10ms
SignalVR
TWR+ = 10ms
TR
1
Output of G- 1, TWG- = 0
Waveforms of signals, VR, Q, Q´ and output TWG-, when the vibrating
system is stationary.
14
Measured output of ZCD, VR (Ch#1), output of OS Q´ (Ch#2), output
of gate G-1, TWG- (Ch#3) at 50Hz and output of synchro Vr (Ch#4)
when the vibrating system is stationary.
15
When the system starts vibrating
Signal Q
50 Hz
TWQ+ = 10ms
Signal Q'
50 Hz
TWQ- =10 ms
TWR+
Signal VR
TR
1
Output of G -1
Waveforms of signals VR, Q, Q´ and output TWG-, when vibration is
started.
16
TABLE 1
RESULTS OF THE VIBRATION
MEASUREMENT
S.No
TWG- (µs) =
TWR+ - TWQ-
1
2
3
4
5
6
7
8
9
10
11
0
153.66
360
455
520
1000
1600
554
400
320
160
Velocity of
Vibrations
(cm/s)
0
4.29
9.94
12.45
14.15
26.03
39.52
-15.02
-11
-8.86
-4.49
Acceleration
(cm/s2)
0
214.5
282.5
125.5
85
594
306
-225
-201
-107
-218.5
17
Output of ZCD (Ch#1), output of OS (Ch#2) and output of gate G-1
(Ch#3) in roll mode at 400ms.
18
Output of ZCD (Ch#1), output of OS (Ch#2) and output of gate G-1 (Ch#3) in
roll mode at 400ms.
19
Measured Output of ZCD (Ch#1), output of OS (Ch#2) and output of
gate G-1 (Ch#3).
20
Measured Output of ZCD (Ch#1), output of OS (Ch#2) and output of gate
G-1 (Ch#3
).
21
Measured Output of ZCD (Ch#1), output of OS (Ch#2) and output of
gate G-1 (Ch#3
).
22
Measured Output of ZCD (Ch#1), output of OS (Ch#2) and output of gate
G-1 (Ch#3
23
Measured Output of ZCD (Ch#1), output of OS (Ch#2) and output of gate
G-1 (Ch#3
24
.
Experimental setup for the measurement of velocity and acceleration.
25
CONCLUSION
• A novel synchro and RMF based seismic
vibration measurement technique is
proposed
• Provides high accuracy and resolution.
• proposed method measures the
vibrations with a resolution of 20 ms
26
CONCLUSION CONTD
• It captures those peaks of vibration
which are missed by conventional
measurement systems due to their
poor resolution.
• fast measurement of velocity and
acceleration of vibrations from the
proposed system will help in the
prediction of earthquakes.
27
CONCLUSION CONTD
• Also proposed method is very
suitable for proper design of
earthquake resistant nuclear power
plants, buildings and structures.
28
REFERENCES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
T. Bleier and F. Freund, 2005. “Earthquake alarm,” IEEE Spectr., vol. 42, no. 12, pp. 22–27, Dec. 2005.
K. Okubo, M. Takayama and N. Takeuchi, “Electrostatic field variation in the atmosphere induced by earth
potential difference variation during seismic wave propagation,” IEEE Trans. on Electromagnetic Compatibility, vol.
49, no. 1, pp.163-169, Feb. 2007.
D. M. Tralli, W. Foxall, A. Rodgers, E. Stappaerts, and C. Schultz, “Suborbital and spaceborne monitoring of seismic
surface waves,” in proc. 2005 IEEE Aerospace Conf., Pasadena, CA, USA, pp. 1- 6.
C. Albertini, Ispra, K. Labibes, and Orino, “Seismic wave measuring devices,” U.S. Patent 6,823,963 B2, Nov. 30,
2004.
P. C. Jenkins, Engineering seismology from earthquakes: observation, theory and interpretation, North Holland, H.
Kanamori and E. Boschi, 1983.
P. Varotsos, K. Alexopoulos, and K. Nomicos, "Seismic electric currents," in Proc. 1981 The Academy of
Athens Conf., pp. 277–286.
P. Varotsos, K. Alexopoulos, K. Nomicos, G. Papaioannou, M. Varotsou and E. Revelioti-Dologlou, "Determination
of the epicenter of impending earthquakes from precursor changes of the telluric current," in Proc. 1981 The
Academy of Athens Conf., pp. 434–446.
P. Varotsos, K. Alexopoulos and K. Nomicos, "Electrotelluric precursors to earthquakes,” in Proc. 1982 The Academy
of Athens Conf., pp. 341–363.
P. Varotsos, K. Alexopoulos, K. Nomicos and M. Lazaridou, “Earthquake prediction and electric signals," Nature, vol.
322, pp. 120, July 1986.
P. Varotsos, N. Sarlis, M. Lazaridou, and P. Kapiris, " Transmission of stress induced electric signals in dielectric
media,” Journal of Applied Physics, vol. 83, pp. 60–70, Jan. 1998.
S. J. Lighthill, A critical review of VAN - Earthquake prediction from seismic electrical signals, London, UK: World
Scientific Publishing Co Pvt. Ltd. 1996, ISBN 978-9810226701.
Y. Y. Kagan, "Special section-assessment of schemes for earthquake prediction; Are earthquakes predictable?"
Geophys. J. Int., vol. 131, pp. 505-525, 1997.
C. Y. King, W. C. Evans, T. Presser, and R. Husk, “Anomalous chemical changes in well water and possible relation to
earthquakes,” Geophys. Res. Lett. vol. 8, pp. 425–428, 1981.
C. Y. King, N. Koizumi and Y. Kitagawa, “Hydrogeochemical anomalies and the 1995 Kobe earthquake,” Science 7,
vol. 269, pp. 38–39, July 1995.
29
REFERENCES CONTD
•
•
•
•
•
•
•
•
N. M. Pérez, P. A. Hernández, G. Igarashi, I. Trujillo, S. Nakai, H. Sumino and H. Wakita, “Searching
and detecting earthquake geochemical precursors in CO2-rich ground waters from Galicia, Spain,”
Geochemical Journal, vol. 42, pp. 75-83, 2008.
P. Mandal, “Crustal shear-wave splitting in the epicentral zone of the 2001 Mw 7.7 Bhuj earthquake,
Gujarat, India,” Journal of Geodynamics, vol. 47, pp. 246–258, 2009.
W.R. Stephenson, “Late resonant response at Wainuiomata, New Zealand, during distant
earthquakes,” Journal of Soil Dynamics and Earthquake Engineering, vol. 25, pp. 187–196, 2005.
E. Durukal, “Critical evaluation of strong motion in Kocaeli and Du¨zce (Turkey) Earthquakes,”
Journal of Soil Dynamics and Earthquake Engineering, vol. 22, pp. 589–609, 2002.
I. M. Taflampas, C. C. Spyrakos and I. A. Koutromanos, “A new definition of strong motion duration
and related parameters affecting the response of medium–long period structures,” Journal of Soil
Dynamics and Earthquake Engineering, vol. 29, pp. 752–763, 2009.
R. Rupakhety, and R. Sigbjornsson, “A note on the L’Aquila earthquake of 6 April 2009: Permanent
ground displacements obtained from strong-motion accelerograms,” Journal of Soil Dynamics and
Earthquake Engineering, vol. 30, pp. 215–220, 2010.
S. J. Arif and Shahedul Haque Laskar, “A rotating magnetic field based high resolution measurement
of velocity and acceleration of seismic vibrations,” The Patent Office Journal 29/04/2011, Issue No.
17/2011, Application No.778/DEL/2011A, pp-7116, April 2011.
Department of Earthquake Engineering, Indian Institute of Technology, Roorki, U.P., India.
30